surface area

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Find the surface area of the cylinder in terms of pi.
I know the formula is SA=LA+2B, but not sure how to plug in the numbers and get answers. Everytime I try I get wrong answer.
The cylinder has I assume radius 8in and height 20in.

352piin^2
320piin^2
832piin^2
448piin^2

• surface area -

Visualize opening up a can (cylinder) and flattening out the pieces.
Don't you have 2 circles + a rectangle ?
The length of the rectangle would be the circumference of the circle, which is 16π

total area = 2circles + 1 rectangle
= 2(π(8^2)) + (16π)(20)
= 128π + 320π = 448π

(the formula you stated was useless to me since You did not define what L, A, and B stand for)

• surface area -

Thank you I see where I messed up, it was on the second spot where you got 320.

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